1. Field of the Invention
The present invention relates to a composition for use as a heavy metal remover and more particularly, the present invention relates to a heavy metal removing composition comprising a polymeric compound having thiuram mono- or poly-sulfide linkage or a mixture thereof. The present invention also relates to a process for removing heavy metals from the environment.
It is well known that public nuisances occurred by the environmental pollution with heavy metals have brought serious social problems. Among them, especially, the poisoning with elemental mercury and compounds thereof are known to show distressing toxic symptoms. Accordingly, it is an important task to establish an effective process for removing heavy metal contaminants from the environment so as to prevent future occurrence of such toxicosis with heavy metals and to clean up the environment already polluted therewith.
The inventors have studied extensively to find an effective way to remove heavy metals and/or compounds thereof from the environment polluted therewith, for example, from solutions and gases, especially from waste water, exhaust gases and the soil already contaminated with, such as agricultural chemicals, and the inventors now found a composition having remarkably high ability to remove heavy metals from the environment, for example, having the ability to reduce mercury concentration contained in a waste water less than 0.02 ppb, and have come to a success in establishing the present invention.
2. Description of the Prior Art
Polymeric compounds having thiuram mono- or poly-sulfide linkage are known and are reported as vulcanization accelerators and bactericides. However, until now, no trial was reported to use said compounds as heavy metal removers to our knowledge. In other words, as far as the inventors know, there is no information about the compounds that they have abilities to remove heavy metals and/or compounds thereof.